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Atmospheric (Air) Quality Assessment Tool for Montana

Environment Technical Note Number MT- 7 (Revision 1)

Revised May 2011

This technical note is also available in Adobe Reader format. If you encounter any problems with the file provided on this page, please contact Technical Resources at 406-587-6822.
Environment Technical Note Number MT-7 (Revision 1; PDF; 306 KB)

By Tom Pick, Water Quality Specialist

Clean Air is identified as one of the six strategic mission goals of the Natural Resources Conservation Service (NRCS) and as such is a critical focus of the agency's technical and financial assistance programs. In addition, emissions of some air quality pollutants are directly linked to water quality impairments in the nation’s surface and ground waters. Adequately recognizing and treating air quality pollution then, is a vitally important consideration in conservation planning.

This assessment tool is intended to help conservation planners and resource managers determine whether or not they have an air quality/atmospheric resource issue or concern. If air quality is identified as a resource concern, the tool can also aid in development of alternatives to address the specific air quality concern identified. Typically, a combination or suite of practices and treatments are utilized to protect or improve atmospheric quality. Resource concerns related to air quality are grouped into five major categories for the purpose of this assessment tool:

  • Particulate matter
  • Ozone
  • Odor
  • Greenhouse Gases
  • Haze

The Clean Air Act of 1970 (CAA) and subsequent amendments established the federal agency (The Environmental Protection Agency (EPA)) and air quality standards to protect and improve the nation’s air. EPA established primary and secondary National Ambient Air Quality Standards (NAAQS) for six criteria air pollutants across the country and Congress directed states to monitor air quality and promulgate, implement, and enforce rules to attain and maintain the NAAQS. The Montana Legislature established and charged the Department of Environmental Quality (DEQ) with implementing and enforcing the 1968 Clean Air Act of Montana which contains provisions additional to the CAA.

To use the tool, read and answer each question in order relative to the setting and conditions on the Conservation Treatment Unit (CTU) in question. For definitions and further explanation of air quality and pollutant terminology used in this technical note, review Appendix 1 prior to using the tool. Activities and appropriate conservation practices are provided as alternatives to address those air pollutants that have common agricultural sources. Lead (Pb) and sulfur dioxide (SO2), two NAAQS criteria air pollutants, are not included in the tool since it is rare for either to originate from an agricultural source.

1. Is the CTU located in a designated non-attainment area or State Implementation Plan (SIP) call area? Yes or No. A Yes answer requires consideration and documentation of the potential agricultural sources and treatment alternatives for the designated criteria pollutant on the CTU. This consideration is for regulated emissions, although in general, agriculture is exempt from air quality regulation in Montana, except as noted (grain elevators and open burning). EPA is currently evaluating the significance of air pollutant emissions from large Concentrated Animal Feeding Operations (CAFOs) to help determine if they should be regulated as a contributing source category. Agricultural sources should be addressed voluntarily in the interest of meeting quality criteria to comply with requirements of the State or Federal Implementation Plans and all applicable Federal, Tribal, State, and local regulations and the NRCS’s mission goal. Circle the applicable pollutant(s) for a DEQ or EPA designated area and complete the appropriate pollutant section of the worksheet. See state non-attainment map below or view it on the Montana DEQ Air Quality Nonattainment Information web page.

Non-Attainment Area Pollutant
  • PM 2.5    
  • PM 10    
  • Carbon Monoxide (CO2)    
  • Lead    
  • Sulfur Dioxide (SO2)

Figure 1. Montana Air Quality Non-attainment Area Map

Figure 1. Montana Air Quality Non-attainment Area Map (State and EPA Designated Areas).

Other - If you answered No to Question 1, do you want to consider methods to evaluate and address atmospheric/air quality concerns and sources as a preventative measure? Yes or No. If yes, continue worksheet. If no, document attainment status in inventory notes and continue evaluating other resource concerns.

Worksheet Assessment and Treatment Alternatives
Appendix 1. Glossary - Explanation of Air Quality Terms